Equipment Media Research Articles

Investigation of dry environment construction Equipment's medium displacement system for submarine pipelines

Innovative underwater pipeline repair and inspection technologies utilising a dry chamber represent a novel approach. This technique involves injecting high-pressure air into a chamber to displace the surrounding medium. However, sealing becomes very challenging owing to the irregularity of the sealing surface, and diver operations pose significant risks at high gas pressures. This study presents a novel design that integrates inflation and drainage methods. It employs an air compressor for chamber inflation and submersible pumps, along with an air-operated diaphragm pump for water drainage. This system could effectively manage various degrees of leakage and maintain continuous drainage, thus establishing a normal pressure environment. Consequently, the sealing requirement is significantly reduced, and divers are allowed to perform multiple tasks within the chamber at atmospheric pressure. Furthermore, the inflation parameters were optimized during the inflation and drainage processes through a numerical method, and the designed system was validated via offshore experiments. The results indicated that the system could handle a leakage rate of 50 m3/h and maintain a dry chamber for at least 5 h.

Estimation of corrosion aggression of aquatic media and corrosion resistance of steels of equipment of oil and gas condensate deposits

Corrosion destruction of the metal of the field equipment and gas pipelines of the oil and gas condensate field (OGCF) was revealed, the cause of which is carbon dioxide corrosion. In order to determine the corrosiveness of the OGCF equipment media, laboratory tests were carried out with periodic moisture condensation in an atmosphere of carbon dioxide, autoclave tests in the liquid phase at elevated temperatures and partial pressure of CO2, and laboratory tests in the gas-vapor phase in the presence of CO2. Tests were carried out on steel 20, the selected solutions were tested on pipe segments of 09G2S steels (well connections and loops) and J55LT (tubing) of 2 types (old, after operation in a well, and new, not operated). Studies have shown that steels used at OGCF (steel 20, J55LT and 09G2S) are not resistant to carbon dioxide corrosion. All items of equipment made of these steels will be potentially weakly resistant to corrosion in the oil and gas condensate field. It is proposed to conduct tests of corrosion inhibitors from various manufacturers in laboratory and field conditions. Recommendations are given for the corrosion inhibitor selected according to the test results. Keywords: local corrosion; aggressiveness of the environment; metal resistance; well piping; plume; tubing; laboratory tests; autoclave tests.

Distribution of impurities in steam-generating equipment in nuclear power and heat-and-electricity plants

A theoretical substantiation and the results of experimental studies of the behavior of impurities in the volume of the boiling medium in equipment in nuclear power and heat-and-electricity plants are presented. It is hypothesized that coarsely dispersed sludge accumulates at the boundary of the turbulent nucleus and viscous sublayer and only a small part of it settles on the heat-transmitting surface. If this hypothesis is correct, then sludge should accumulate and be expelled into the main volume of the working medium when the heat load changes, just like soluble impurities. The experimental data confirm this hypothesis.

Construction materials for reaction unit in the liquid-phase synthesis of propylene oxide

The main components of the reaction medium in equipment for the synthesis of propylene oxide by liquid-phase oxidation of gaseous propylene with peracetic acid are propylene, peracetic acid, ethyl acetate, acetic acid, propylene oxide, carbon dioxide, oxygen, methane, and propylene glycol acetates. The operating conditions of the equipment and content of the main components of the medium are shown. Results are given for the investigation of the corrosion behavior of 12Kh18N10T, 10Kh17N13M2T, 08Kh22N6T, and 08Kh21N6M2T steels, AD0 and AD1 aluminum, and VT1-0 titanium. VSt3 carbon steel was tested for comparison.